Method of impregnating regenerated cellulose rope



Patented Jan. 27, 1948 I UNITED STATES PATENT OFFICE METHOD OF IMPREGNATING REGENER- ATED CELLULOSE ROPE Henry Dreyfus, London, and Donald Finlayson and Richard Gilbert Perry, Spondon, near Derby, England; Claude Bonard, administrator of said Henry Dreyfus, deceased, assignors, by direct and mesne assignments, to Celanese Corporation of America, a corporation of Delaware 4 No Drawing. Application December 21, 1943, Serial No. 515,144. In Great Britain March 26,

Section 1, Public Law 690, August 8, 1946 Patent expires December 9, 1962 2 Claims. (Cl. 117-143) This invention relates to the manufacture of ropes and like textile materials, for example twines and cords of regenerated cellulose, and is a continuation-in-part of our U. S. application No. 437,992, filed on April '7, 1942, now abandoned.

We have found that the physical properties of materials of the kind referred to above, can be improved by impregnating them with a-composition comprising a water resistant cellulose ester or ether. The composition may also include a plasticiser or softener for said ester or ether.

By the process of the invention ropes, cords and like products can be made which are compact, have a desirable handle, and are of considerably higher wet tenacity than the untreated materials, and substantially water proof.

It is of advantage to apply the cellulose ester or ether in non-aqueous solution at an elevated temperature e. g., 50-60 of 100 C. and better still above the boiling point of water. Under such conditions the moisture content of the materials treated is very low, and this appears to contribute to the high wet tenacity of the treated materials.

The following example illustrates the invention:

Example A rope of regenerated cellulose yarns of tenacity between 3 and 6 grms, per denier, made by stretching cellulose acetate yarns in steam and completely saponifying the stretched yarns, is impregnated with a solution made by incorporating in a commercial ethyl cellulose 40% of its weight of castor oil and dissolving the resulting composition in a mixture of 90 parts of xylene and 10 parts butanol to form a solution containing 3-5% of the ethyl cellulose. The impregnation is effected at a temperature of about,

ethyl used, e. g., other non-drying vegetable oils, or water resistant plasticiser for the ethyl cellulose, e. g., tricresyl phosphate may be employed in the proportion of 15% on the weight of the ethyl cellulose. Other plasticisers that may be used include dimethyl phthalate, dimethoxyphthalate and tri-(mono-chlorethyl) phosphate.

The ropes or other products treated may be formed from continuous filament yarns, staple fibre yarns or stapilised or abraded yarns. The filaments or fibres of regenerated cellulose from which the yarns are formed may be produced by any suitable process, for example, by the viscose process, the cuprammonium process, or by the saponification of filaments or fibres of an organic ester of cellulose. The process of the invention is of particular advantage in connection with the treatment of twines, cords and ropes composed of or containing high tenacity filaments or fibres of regenerated cellulose. High tenacity filaments may be obtained by a spinning process in the course of which the filaments are stretched very considerably. or by the complete saponification of high tenacity filaments or fibres of an organic ester of cellulose, such as can be made for example by stretching filaments or fibres of the cellulose ester of ordinary tenacity in steam, hot water, or an organic stretch-assisting agent. Such high tenacity regenerated cellulosic filaments or fibres may have a dry tenacity of over 2 gms. per denier, for example 2.5 to 3, 4 or even more than 5 gms. per denier. The wet tenacity of such products is in general much lower than their dry tenacity. For some purposes this fact prevents full advantage being taken of the extraordinarily high dry tenacities of some of these products. The present invention, by enabling the wet tenacity to be considerably increased, greatly increases the utility of the products in question. The invention includes the treatment of twines, cords, ropes and other products containing regenerated cellulosic filaments or fibre whether of a normal low or high tenacity, in admixture with other textile materials, of natural origin, for example, cotton, linen, jute, ramie, hemp, manilla, silk and wool, or of artificial origin, for example cellulose esters or ethers, polymerlsed vinyl esters or ethers, or filament-forming polyamides.

Ethyl cellulose has been instanced above as a water resistant cellulose ester or ether which can be employed with advantage in the process of the invention. Among other cellulose esters or others which can be so employed are: other water resistant ethers of cellulose, for example, propyl cellulose, benzyl cellulose, butyl cellulose, ethyl butyl cellulose, hexyl cellulose and ethyl hexyl cellulose; and cellulose esters, especially higher fatty acid esters, for example cellulose propionate, cellulose butyrate, cellulose acetate-propionate, cellulose acetate-butyrate, cellulose stearate, cellulose palmitate, cellulose acetate-stearate, cellulose acetate-palmitate, and cellulose laurate. As indicated above it is of advantage to have present in the comppsition containing the film forming ester or ether, a plasticiser or softener therefor, and this should be water resistant. Apart from tricresyl phosphate, referred to above, other plasticisers which are phosphoric esters have been found suitable, for example triphenyl phosphate and tri-(monochlor butyl) phosphate. Certain fixed vegetable oils have also proved satisfactory,

e. g., castor oil, olive oil and palm oil. Drying oils such as linseed oil and cotton seed oil are less satisfactory, as are mineral oils.

'The treatment may be applied at any convenient stage in the manufacture of the products. Thus, in the manufacture of ropes of regenerated cellulose, the treatment may be applied to thefilaments or fibres from which the yarns are made, to the yarns themselves, to the strands into which the yarns are formed, or to the rope itself. It is preferred, however, to effect the im-- pregnation with the cellulose ester or ether to the rope as such, rather than to the components from which the rope is to the formed.

Having described our invention, what We desire to secure by Letters Patent is:

1. Process for improving the properties of rope composed offilaments of regenerated cellulose 4 of tenacity at least 2 grams per denier, which comprises impregnating said rope with a solution of a derivative of cellulose of low water-absorption, said derivative being ethyl cellulose, together witha-bout 40% of its weight of castor oil, in a mixture of butanol and Xylene, said solution containing about 35% of the ethyl cellulose, the impregnation being carried out at from to 100 C.

2. Process for improving the properties of rope composed of filaments of regenerated cellulose of tenacity .at least 2 grams per denier, which comprises impregating said rope with a solution of a derivative of cellulose of low water-absorption, said derivative being ethyl cellulose, together with about 40% of its weight of castor oil, in a mixture of 1 part of butanol and 9 parts of xylene, said solution containing about 3-5% of the ethyl cellulose, the impregnation being carried out at about -70 C.

HENRY DREYFUS.

DONALD FINLAYSON.

RICHARD GILBERT PERRY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 590,842 Kennedy Sept. 28,1897 2,013,825 Fordyce .et al Sept. 10, 193.5 2,107,852 Bolton Feb. 8, 1938 2,147,736 Dreyfus 1Feb. 21, 1939 2,184,502 Metcalf Dec. '26, 1939 2,301,480 Trowell Nov. 10, 1942 2,319,312 Finlayson May 18, 1943 2,353,224 Dreyfus July 11, 1944 2,353,225 Dreyfus July 11, 1944 2,376,813 Robins et al May 22, 1945 

